FOOTNOTES:
[E] Adapted from Banks, Nuttall, Warburton, Stiles, et al.
[F] Dr. C. W. Stiles considers the species which is responsible for spotted fever distinct from the venustus of Banks, separating it as follows:
Goblet cells about 75 in the male or 105 in the female. Texas. D. venustus.
Goblet cells 157 in the male, or 120 in the female; stigmal plate shaped as shown in the figure ([figs. 150 a, b]). Montana, etc. D. andersoni.
[G] Professor C. R. Crosby who has been working upon certain capsids states that he and his assistant have been bitten by Lygus pratensis, the tarnished plant bug, by Chlamydatus associatus and by Orthotylus flavosparsus, though without serious results.
[H] Species marked with an * are known to transmit malaria. Species found only in tropical North America and not known to carry malaria have been omitted from this table, but all found in the United States are included.
[I] This table to the North American genera of the Tabanidæ is adapted from one given by Miss Ricardo.
[J] The classification of the Muscoidea as set forth by Schiner and other earlier writers has long been followed, although it is not satisfactory, being admittedly more or less artificial. Within the last two or three decades several schemes have been advanced, that of Brauer and Bergenstamm and of Girschner, with the modifications of Schnabl and Dziedzicki having obtained most favor in Europe. Townsend, in 1908, proposed a system which differs from Girschner's in some respects, but unfortunately it has not yet been published in sufficient detail to permit us to adopt it. From considerations of expediency we use here the arrangement given in Aldrich's Catalogue of North American Diptera, though we have drawn very freely upon Girschner's most excellent paper for taxonomic characters to separate the various groups.
It may sometimes be found that a species does not agree in all the characters with the synopsis; in this case it must be placed in the group with which it has the most characters in common.
[K] There are several genera of flies of the family Cordyluridæ; (i.e. Acalyptratæ) which might be placed with the Anthomyiidæ (i.e. Calyptratæ), owing to the relatively large size of their squamæ. As there is no single character which will satisfactorily separate all doubtful genera of these two groups we must arbitrarily fix the limits. In general those forms on the border line having a costal spine, or lower squama larger than the upper, or the lower surface of the scutellum more or less pubescent, or the eyes of the male nearly or quite contiguous, or the eyes hairy, or the frontal setæ decussate in the female; or any combination of these characters may at once be placed with the Anthomyiidæ. Those forms which lack these characteristics and have at least six abdominal segments (the first and second segments usually being more or less coalescent) are placed with the Acalyptrates. There are other acalyptrates with squamæ of moderate size which have either no vibrissæ, or have the subcosta either wholly lacking or coalescent in large part with R1 or have spotted wings; they, therefore will not be confused with the calyptrates.
[L] Pachymyia Macq. is closely related to Stomoxys. It differs in having the arista rayed both above and below. P. vexans, Brazil.
[M] The genus Eudasyphora Town. has recently been erected to contain D. lasiophthalma.
[N] Nitellia, usually included in this genus has the apical cell petiolate. Apollenia Bezzi, has recently been separated from Pollenia to contain the species P. nudiuscula. Both genera belong to the Eastern hemisphere.
[O] The following three genera are not sufficiently well defined to place in this synopsis. In color and structural characters they are closely related to Cynomyia from which they may be distinguished as follows. Catapicephala Macq., represented by the species C. splendens from Java, has the setæ on the facial ridges rising to the base of the antennæ and has median marginal macrochætæ on the abdominal segments two to four: Blepharicnema Macq., represented by B. splendens from Venezuela has bare genæ, oral setæ not ascending; tibiæ villose; claws short in both sexes; Sarconesia Bigot with the species S. chlorogaster from Chile, setose genæ; legs slender, not villose; claws of the male elongate.
[P] Plinthomyia Rdi. and Hemigymnochæta Corti are related to Ochromyia, though too briefly described to place in the key.
APPENDIX
HYDROCYANIC ACID GAS AGAINST HOUSEHOLD INSECTS
The following directions for fumigating with hydrocyanic acid gas are taken from Professor Herrick's circular published by the Cornell Reading Course:
Hydrocyanic acid gas has been used successfully against household insects and will probably be used more and more in the future. It is particularly effective against bed-bugs, and cockroaches, but because it is such a deadly poison it must be used very carefully.
The gas is generated from the salt potassium cyanid, by treating it with sulfuric acid diluted with water. Potassium cyanid is a most poisonous substance and the gas emanating from it is also deadly to most, if not all, forms of animal life. The greatest care must always be exercised in fumigating houses or rooms in buildings that are occupied. Before fumigation a house should be vacated. It is not necessary to move furniture or belongings except brass or nickel objects, which may be somewhat tarnished, and butter, milk, and other larder supplies that are likely to absorb gas. If the nickel and brass fixtures or objects are carefully covered with blankets they will usually be sufficiently protected.
There may be danger in fumigating one house in a solid row of houses if there is a crack in the walls through which the gas may find its way. It also follows that the fumigation of one room in a house may endanger the occupants of an adjoining room if the walls between the two rooms are not perfectly tight. It is necessary to keep all these points in mind and to do the work deliberately and thoughtfully. The writer has fumigated a large college dormitory of 253 rooms, once a year for several years, without the slightest accident of any kind. In order to fumigate this building about 340 pounds of cyanid and the same amount of sulfuric acid were used each time. In addition to this, the writer has fumigated single rooms and smaller houses with the gas. In one instance the generating jars were too small; the liquid boiled over and injured the floors and the rugs. Such an accident should be avoided by the use of large jars and by placing old rugs or a quantity of newspapers beneath the jars.
The Proportions of Ingredients
Experiments and experience have shown that the potassium cyanid should be ninety-eight per cent pure in order to give satisfactory results. The purchaser should insist on the cyanid being of at least that purity, and it should be procurable at not more than forty cents per pound. The crude form of sulfuric acid may be used. It is a thickish, brown liquid and should not cost more than four or five cents a pound. If a room is made tight, one ounce of cyanid for every one hundred cubic feet of space has been shown to be sufficient. It is combined with the acid and water in the following proportions:
| Potassium cyanid | 1 ounce |
| Commercial sulfuric acid | 1 fluid ounce |
| Water | 3 fluid ounces |
A Single Room As an Example
Suppose a room to be 12 by 15 by 8 feet. It will contain 12 × 15 × 8, or 1440 cubic feet. For convenience the writer always works on the basis of complete hundreds; in this case he would work on the basis of 1500 cubic feet, and thus be sure to have enough. The foregoing room, then, would require 15 ounces of cyanid, 15 ounces of sulfuric acid, and 45 ounces of water. The room should be made as tight as possible by stopping all the larger openings, such as fireplaces and chimney flues, with old rags or blankets. Cracks about windows or in other places should be sealed with narrow strips of newspaper well soaked in water. Strips of newspaper two or three inches wide that have been thoroughly soaked in water may be applied quickly and effectively over the cracks around the window sash and elsewhere. Such strips will stick closely for several hours and may be easily removed at the conclusion of the work.
While the room is being made tight, the ingredients should be measured according to the formula already given. The water should be measured and poured first into a stone jar for holding at least two gallons. The jar should be placed in the middle of the room, with an old rug or several newspapers under it in order to protect the floor.
The required amount of sulfuric acid should then be poured rather slowly into the water. This process must never be reversed; that is, the acid must never be poured into the jar first. The cyanid should be weighed and put into a paper bag beside the jar. All hats, coats, or other articles that will be needed before the work is over should be removed from the room. When everything is ready the operator should drop the bag of cyanid gently into the jar, holding his breath, and should walk quickly out of the room. The steam-like gas does not rise immediately under these conditions, and ample time is given for the operator to walk out and shut the door. If preferred, however, the paper bag may be suspended by a string passing through a screw eye in the ceiling and then through the keyhole of the door. In this case the bag may be lowered from the outside after the operator has left the room and closed the door.
The writer has most often started the fumigation toward evening and left it going all night, opening the doors in the morning. The work can be done, however, at any time during the day and should extend over a period of five or six hours at least. It is said that better results will be obtained in a temperature of 70° F., or above, than at a lower degree.
At the close of the operation the windows and doors may be opened from the outside. In the course of two or three hours the gas should be dissipated enough to allow a person to enter the room without danger. The odor of the gas is like that of peach kernels and is easily recognized. The room should not be occupied until the odor has disappeared.
Fumigating a Large House
The fumigation of a large house is merely a repetition, in each room and hall, of the operations already described for a single room. All the rooms should be made tight, and the proper quantities of water and sulfuric acid should be measured and poured into jars placed in each room with the cyanid in bags besides the jars. When all is ready, the operator should go to the top floor and work downward because the gas is lighter than air and tends to rise.
Precautions
The cyanid should be broken up into small pieces not larger than small eggs. This can best be done on a cement or brick pavement. It would be advantageous to wear gloves in order to protect the hands, although the writer has broken many pounds of cyanid without any protection on the hands. Wash the hands thoroughly at frequent intervals in order to remove the cyanid.
The operations of the work must be carried out according to directions.
The work should be done by a calm, thoughtful and careful person—best by one who has had some experience.
Conspicuous notices of what has been done should be placed on the doors, and the doors should be locked so that no one can stray into the rooms.
The gas is lighter than air, therefore one should always begin in the rooms at the top of the house and work down.
After fumigation is over the contents of the jar should be emptied into the sewer or some other safe place. The jars should be washed thoroughly before they are used again.
It must be remembered that cyanid is a deadly poison; but it is very efficient against household insects, if carefully used, and is not particularly dangerous when properly handled.
LESIONS PRODUCED BY THE BITE OF THE BLACK-FLY
While this text was in press there came to hand an important paper presenting a phase of the subject of black fly injury so different from others heretofore given that we deem it expedient to reproduce here the author's summary. The paper was published in The Journal of Cutaneous Diseases, for November and December, 1914, under the title of "A Clinical, Pathological and Experimental Study of the Lesions Produced by the Bite of the Black Fly (Simulium venustum)," by Dr. John Hinchman Stokes, of the University of Michigan.